Malaysia - A Malaysian teacher has defended her move to punish 170 teenage girls by making them squat neck-deep in a fish pond, in a case that has sparked concerns about abuse in schools, a report said Monday.

Wee Yim Pien, an English teacher and warden at a boarding school in Sarawak state on Borneo island, told The Star newspaper that she sent the girls into the pond for 30 minutes on Wednesday after they repeatedly ignored her warnings to stop throwing sanitary pads into toilet bowls.

Wee, 27, denied that the pond water was dirty, saying the water was often used for washing and the school had also conducted obstacle courses in the pond, the report said.

Comment: Could we say a lack of conscience?

The case came to light over the weekend after Parent-Teacher Association chairman Jimmy Kiu took photographs of the incident and sent them to local newspapers to protest the harsh punishment.

Kiu, who also runs the school's catering operation, claimed it was raining heavily at the time, and some of the girls fell sick and later got rashes due to the dirty water, the New Straits Times said.

Some national teachers unions have protested Wee's action, saying it was unwarranted and amounted to abuse.

Education Minister Hishammuddin Hussein has promised an investigation into the case.

Sarawak education officials were not immediately available for comments Monday. Phone calls to the school went unanswered.